Document Type : RESEARCH PAPER
Surgery and perioperative care, Dell Medical School -- The University of Texas at Austin
Radboud university medical center, Radboud Institute for Health Sciences, Department of Surgery, Nijmegen, the Netherlands
Orthopaedic surgery, Amsterdam University Medical Center, Amsterdam, The Netherlands
Occupational Medicine & Pain Management, OccMD Group, Texas Health Dallas, Dallas, Texas, USA
Dell Medical School -- The University of Texas at Austin
Background: Newly symptomatic chronic musculoskeletal illness is often misinterpreted as new pathology, particularly
when symptoms are first noticed after a noxious event. In this study, we were interested in the accuracy and reliability of
identifying the symptomatic knee based on bilateral MRI reports.
Methods: We selected a consecutive sample of 30 occupational injury claimants, presenting with unilateral knee
symptoms who had bilateral MRI on the same date. A group of blinded musculoskeletal radiologists dictated diagnostic
reports, and all members of the Science of Variation Group (SOVG) were asked to indicate the symptomatic side based
on the blinded reports. We compared diagnostic accuracy in a multilevel mixed-effects logistic regression model, and
calculated interobserver agreement using Fleiss’ kappa.
Results: Seventy-six surgeons completed the survey. The sensitivity of diagnosing the symptomatic side was 63%,
the specificity was 58%, the positive predictive value was 70%, and the negative predictive value was 51%. There was
slight agreement among observers (kappa= 0.17). Case descriptions did not improve diagnostic accuracy (Odds Ratio:
1.04; 95% CI: 0.87 to 1.3; P=0.65).
Conclusion: Identifying the more symptomatic knee in adults based on MRI is unreliable and has limited accuracy, with or
without information about demographics and mechanism of injury. With a dispute concerning the extent of the injury to a knee
in a litigious, medico-legal setting such as Workers’ Compensation, consideration should be given to obtaining a comparison
MRI of the uninjured, asymptomatic extremity.
Level of evidence: II